func (g *GPIO) Host() (string, error) {
host, _, err := embd.DetectHost()
if err != nil {
return "", err
}
return string(host), nil
}
func (g *GPIO) Close() error {
// close all the pins we have open if any
for _, pinState := range g.pinStates {
if pinState.Pin != nil {
switch pinObj := pinState.Pin.(type) {
case embd.DigitalPin:
pinObj.Close()
case embd.PWMPin:
pinObj.Close()
case BlasterPin:
pinObj.Close()
}
}
}
// if its a raspberry pi close pi-blaster too
host, _, err := embd.DetectHost()
if err != nil {
return err
}
if host == embd.HostRPi {
CloseBlaster()
}
err = embd.CloseGPIO()
if err != nil {
return err
}
return nil
}
func (g *GPIO) Init(pinStateChanged chan PinState, pinAdded chan PinState, pinRemoved chan string, states map[string]PinState) error {
g.pinStateChanged = pinStateChanged
g.pinRemoved = pinRemoved
g.pinAdded = pinAdded
g.pinStates = states
// if its a raspberry pi initialize pi-blaster too
host, _, err := embd.DetectHost()
if err != nil {
return err
}
if host == embd.HostRPi {
InitBlaster()
}
err = embd.InitGPIO()
if err != nil {
return err
}
// now init pins
for key, pinState := range g.pinStates {
if pinState.Name == "" {
pinState.Name = pinState.PinId
}
g.PinInit(key, pinState.Dir, pinState.Pullup, pinState.Name)
g.PinSet(key, pinState.State)
}
return nil
}
func detect(c *cli.Context) {
host, rev, err := embd.DetectHost()
if err != nil {
fmt.Println(err)
os.Exit(1)
}
fmt.Printf("detected host %v (rev %v)\n", host, rev)
}
func ledToBlink() string {
host, _, err := embd.DetectHost()
panicIf(err)
switch host {
case embd.HostRPi:
return "LED0"
case embd.HostBBB:
return "USR3"
}
panic("Unsupported host")
}
func init() {
configFile = flag.String("conf", "", "IoT app configuration file")
flag.Parse()
switch h, _, err := embd.DetectHost(); h {
case embd.HostRPi:
host = NewRPi()
case embd.HostBBB:
host = NewBeagleBone()
default:
if err != nil {
panic(err)
}
}
}
func main() {
flag.Parse()
h, _, err := embd.DetectHost()
if err != nil {
return
}
var pinNo interface{}
switch h {
case embd.HostBBB:
pinNo = "P9_31"
case embd.HostRPi:
pinNo = 10
default:
panic("host not supported (yet :P)")
}
if err := embd.InitGPIO(); err != nil {
panic(err)
}
defer embd.CloseGPIO()
led, err := embd.NewDigitalPin(pinNo)
if err != nil {
panic(err)
}
defer led.Close()
if err := led.SetDirection(embd.Out); err != nil {
panic(err)
}
if err := led.Write(embd.High); err != nil {
panic(err)
}
time.Sleep(1 * time.Second)
if err := led.SetDirection(embd.In); err != nil {
panic(err)
}
}
func (g *GPIO) PinInit(pinId string, dir Direction, pullup PullUp, name string) error {
var pin interface{}
state := byte(0)
if dir == PWM {
host, _, err := embd.DetectHost()
if err != nil {
return err
}
if host == embd.HostRPi {
// use pi blaster pin
log.Println("Creating PWM pin on Pi")
// get the host descriptor
desc, err := embd.DescribeHost()
if err != nil {
return err
}
// get the pinmap
embdMap := desc.GPIODriver().PinMap()
// lookup the pinId in the map
var pinDesc *embd.PinDesc
for i := range embdMap {
pd := embdMap[i]
if pd.ID == pinId {
pinDesc = pd
break
}
for j := range pd.Aliases {
if pd.Aliases[j] == pinId {
pinDesc = pd
break
}
}
}
if pinDesc != nil {
// we found a pin with that name....what is its first Alias?
pinIdInt, err := strconv.Atoi(pinDesc.Aliases[0])
if err != nil {
log.Println("Failed to parse int from alias : ", pinDesc.Aliases[0])
return err
}
p := NewBlasterPin(pinIdInt)
pin = p
} else {
log.Println("Failed to find Pin ", pinId)
return errors.New("Failed to find pin " + pinId)
}
} else {
// bbb, so use embd since pwm pins work there
p, err := embd.NewPWMPin(pinId)
if err != nil {
log.Println("Failed to create PWM Pin using key ", pinId, " : ", err.Error())
return err
}
pin = p
}
} else {
// add a pin
p, err := embd.NewDigitalPin(pinId)
if err != nil {
return err
}
pin = p
err = p.SetDirection(embd.Direction(dir))
if err != nil {
return err
}
if pullup == Pull_Up {
err = p.PullUp()
// pullup and down not implemented on rpi host so we need to manually set initial states
// not ideal as a pullup really isn't the same thing but it works for most use cases
if err != nil {
log.Println("Failed to set pullup on " + pinId + " setting high state instead : " + err.Error())
// we failed to set pullup, so lets set initial state high instead
err = p.Write(1)
state = 1
if err != nil {
return err
}
}
} else if pullup == Pull_Down {
err = p.PullDown()
if err != nil {
log.Println("Failed to set pulldown on " + pinId + " setting low state instead : " + err.Error())
err = p.Write(0)
state = 1
if err != nil {
return err
}
}
}
}
// test to see if we already have a state for this pin
existingPin, exists := g.pinStates[pinId]
if exists {
existingPin.Pin = pin
existingPin.Name = name
existingPin.Dir = dir
existingPin.State = state
existingPin.Pullup = pullup
g.pinStates[pinId] = existingPin
g.pinStateChanged <- existingPin
g.pinRemoved <- pinId
g.pinAdded <- g.pinStates[pinId]
} else {
g.pinStates[pinId] = PinState{pin, pinId, dir, state, pullup, name}
g.pinAdded <- g.pinStates[pinId]
}
return nil
}
